1. Field of the Invention
The present invention relates to multimedia authentication and more particularly to a two level cross-correlation based system for watermarking continuous digital media. The primary area for the application of the present invention is the content authentication and ownership identification for continuous digital media that are prone to active attacks such as unauthorized removal and unauthorized embedding. Furthermore, to protect the watermarks from being easily tampered or detected by unauthorized personnel, a method of “two level cross-correlation” is thus introduced while watermarks are being created.
2. Description of the Related Art
Watermarking has been widely used for the applications of multimedia authentication and copyright protection. Video watermarking, in particular, is unique to other types of media watermarking in that it deals primarily with real-time continuous bitstreams. Many prior art references have focused on watermarking at the video compression level. See for example, D. Simitopoulos, N. Zissis, P. Georgiadis, V. Emmanouilidis, and M. G. Strintzis, “Encryption and watermarking for the secure distribution of copyrighted MPEG video on DVD,” Multimedia Systems 9: pp 217-227, 2003; N. J. Mathai, D. Kundur, and A. Sheikholeslami, “Hardware Implementation Perspectives of Digital Video Watermarking Algorithms,” IEEE Transactions on Digital Signal Processing, Vol. 51, No. 4, April 2003; S. W. Kim and S. Suthaharan, “An Entropy Masking Model for Multimedia Content Watermarking,” Proceedings of the 37th Hawaii International Conference on System Sciences, 2004; W. Zhu, Z. Xiong, and Y. Q. Zhang, “Multiresolution Watermarking for Images and Video,” IEEE Transactions on Circuits and Systems for Video Technology, Vol. 9, No. 4, June 1999; M. Maes, T. Kalker, J-P. Linnartz, J. Talstra, G. Depovere, and J. Haitsma, “Digital Watermarking for DVD Video Copy Protection,” IEEE Sigmal Processing Magazine, September 2000. Although these methods generally produce good protection by taking into consideration the information contents of the underlying video, they tend to consume extra processing power that can otherwise be used to improve the performance of the encoder and/or reduce the latencies caused by time-critical tasks.
As will be disclosed below, the present invention provides for an efficient implementation of video watermarking at the system level and yet produces good protection and authentication on the recorded videos.